Mt. Ontake, a volcano in central Japan erupted unexpectedly yesterday surprising scientists and some 200 hikers on its slopes. So far, more than two dozen bodies of victims have been recovered by rescuers. Volcanoes in Japan are monitored closely and checked for signs of imminent eruption such as increased earthquake activity. But Mt. Ontake came alive yesterday without any warning whatsoever, blanketing its slopes - and everything on them - under a thick layer of ash.

Edwards' Dodo: painted by Roelant Savery in 1626Courtesy Public domain via WikipediaDeath of individuals is a fact of life, and in the same way so is extinction of species. An animal species lasts, on average, about 4 million years. It's claimed that 99 percent (or more!) of all species that have ever lived on Earth are now extinct. (If you are wondering how that number was calculated, you can read a couple explanations here).

Most of the life-forms pictured have been confirmed as extinct by the International Union for the Conservation of Nature (IUCN) along with a few others from reliable sources. That's not to say some straggling thought-to-be-gone individuals won't be sighted in some obscure location in the future but until then they'll be considered extinct.

The compilation not only gives a good picture of the diversity of life on our planet but also a good idea of the fragility of the biosphere.

Using a remotely operated vehicle (ROV), researchers on the Nautilus Live expedition came across something they hadn't seen before - a rare, purple siphonophore. Personally, I wasn't aware such a bizarre organism existed until I saw this video. But there it is, scooting across the ocean floor, probably looking for something to eat. It may look like a single organism but it's actually a whole colony of single organisms called zooids. Siphonophores are members of Cnidaria, an animal phylum that includes true jellyfish, corals and hydroids.

Gesundheit!: Viral illness is spreading through the MidwestCourtesy SCA Svenska Cellulosa Ak...An unusually high number of cases of Enterovirus D68 (EV-D68) have been showing up recently in clinics and hospitals in the Midwest. The U.S. Center for Disease Control and Prevention says EV-D68 (related to the common cold) is a mild to severe upper respiratory illness that can cause wheezing and coughing and in some cases even more severe symptoms can develop. Some patients can be treated with a nebulizer but others - such as those afflicted with asthma - can develop even more dangerous conditions. In one reported case, an infected child's lungs were disturbed to such a degree, he had to be placed on a blood oxygenator.

The outbreak is affecting mostly school-aged children because they haven't yet built up their immune systems like adults have. And even previously healthy children are getting sick. Between 2009 and 2013 the CDC reported only 79 cases of EV-D68, but already this year there have been more cases confirmed than in any previous year.

The illness can be spread through aerosol transmission via coughing or sneezing or by direct contact with a person or surface containing the virus. The best prevention against the virus is for adults and children to wash their hands regularly.

Paleontologist Ernst Stromer: Discoverer of original Spinosaurus aegyptiacus.Courtesy Public domain via WikipediaBack in 1911, German paleontologist Ernst Stromer discovered and described the remains of a then new Cretaceous dinosaur he named Spinosaurus aegyptiacus. The strange beast sported a huge sail framed around a series of giant spines that ran down its back. Unfortunately, all Stromer's fossil evidence was destroyed during the hostilities of WW II, when the British Royal Air Force bombed the Munich museum where the fossils were stored. Only a few scientific drawings and a single photograph remain.

Ninety years later an international team of researchers led by paleontologist Nizar Ibrahim returned to Stromer's original dig site and discovered additional specimens of Spinosaurus aegyptiacus, and in studying their fossils have come to some startling new conclusions about the strange dinosaur.

Spinosaurus aegyptiacusCourtesy University of Chicago Fossil LabSpinosaurus was a big boy - nine feet longer than the largest known Tyrannosaurus rex. And despite a long-held notion that dinosaurs were strictly terrestrial - i.e. they only dwelled on land (although like us, they probably occasionally swam in water), S. aegyptiacus appears to have spent much of his life in water, feeding on fish, and when on land (e.g to lay eggs) probably walked on all-fours, unlike every other known predatory dinosaur.

Imagine the thrill of doing something like this. Adventurers George Kourounis and Sam Cossman, along with two other fellow explorers spent four days investigating Marum Crater on Ambrym Island in the South Pacific. Kourounis and Cossman made two descents into the cauldron to capture this spectacular (if not totally insane) footage. Somebody had to do it.

StonehengeCourtesy Lucille PineStonehenge, the ancient semi-ring of massive sarsen stones standing upright on England's Salisbury Plain continues to give up more of its secrets. Recent analysis of grassy areas long thought to be stone-free may well have contained rock slabs that formed a complete circle with the rest of the huge monoliths. An English Heritage steward, employed to maintain the antiquity grounds, said because the water hose couldn't reach the far end of the site, he noticed some patches of parched grass that seemed to indicate stones had once stood on the spots. Archeologists were brought in to examine the evidence, and published their study in the archaeological journal Antiquity.

A walking test rock in Death Valley: A test rock fitted with a GPS unit shows evidence of movement across the ice covered Racetrack Playa in Death Valley.Courtesy Mike Hartmann via PLoS OneSince the 1940s the "walking rocks" of Death Valley's Racetrack Playa have mystified visitors and scientists alike. Rocks of various size (up to 700 lbs!) somehow move across the dry lakebed. Nobody ever seemed to witness their actual movement, but the rocks definitely did move, leaving long telltale tracks behind. What was the cause? High winds? Slippery slopes of algae? Aliens? No one could say for certain.

The unusual phenomenon, it turns out, requires a special sequence of events that the environment at Racetrack Playa evidently provides.

The first step requires the playa's basin to fill with just enough water to surround the rocks but not too deep to cover them. Next, as nighttime temperatures fall, the water freezes into a quarter-inch thick sheet of ice. In the morning, as the rising sun begins to melt the ice sheet, it causes it to break into smaller floating panels. Finally, light winds - as light as 10mph in strength - gently blow these panels into the rocks and push them across the playa at a speed of only a few inches per second. Since the movement of the rocks is synchronized, even if someone was observing the phenomenon directly, they may not notice the rocks are moving.

In 2011, the research team, led by co-authors Jim Norris and Richard Norris, positioned their own sample blocks of limestone on the dry lakebed each fitted with a GPS unit to record movement (park authories wouldn't allow them use any native rocks). A high-resolution weather station was also set up to measure wind velocity. A magnet positioned beneath each sample rock triggered the GPS devices once the rocks began to move. Since all the special conditions had to be met in order for the rocks to move, the researchers were somewhat suprised when they returned two years later to see a pond of three inches of water covering the playa. It was a perfect set-up to study their hypothesis. Eventually ice formed on the pond's surface, and at the very end of 2013 it began to break up and move the rocks in the process. A camera recorded timelapse of each event.

"We documented five movement events in the two and a half months the pond existed and some involved hundreds of rocks," said Richard Norris, "So we have seen that even in Death Valley, famous for its heat, floating ice is a powerful force in rock motion."